Lifespan/Longevity

<p>Dugongs have lifespans of 70 years or more in the wild, which is estimated by counting the growth layers that make up a dugong’s tusks. However, they are prone to a extensive array of parasites and diseases, some of which are infectious. Dugongs are difficult to keep in captivity due to their specialized diet, which is expensive to provide as the specific type of seagrasses cannot be grown in captivity. Calves are rarely seen in captivity because they suckle for about 18 months after birth. Only one orphaned calf has ever been successfully introduced into captivity in Australia.<span> (Lawler et al., 2002; Marsh et al., 2002)</span></p>